The invention relates to a space keeper for inserting between two vertebrae, the space keeper having an adjustable axial length and a sleeve-like first member and a second member guided in the latter and movable in the axial direction relative to the first member for setting an overall length.
A space keeper of this type is known from EP 0 977 528 A1. In this the two members in the telescoped position are inserted between two vertebrae and then pulled apart by hand to the desired length and then locked in the extended position.